bug#13229: 24.3.50; Crash with ns_run_ascript

[Carsten Bormann]

I regularly use this little function:

(defun insert-safari-topmost ()
  (interactive "*")
  (insert
   (substring
    (do-applescript "
tell application \"Safari\"
set myUrl to URL of document 1 as string
end tell
return myUrl
")
    1 -1))
  (insert "\n")
  (insert
   (do-applescript "
tell application \"Safari\"
set myName to name of document 1 as string
end tell
return myName
"))
  (insert "\n"))

This little hack has worked perfectly for a couple of years.
I try to stay relatively current with the nightlies on emacsformacosx, updating 
once a week or so.
Recently (starting for me on December 7, probably based on an Emacs from
December 4), this has developed a problem.
Randomly (at maybe 1 % probability, with a pattern that I can't
discern), this crashes like the below.
Restarting Emacs, and performing the same Applescript in the same
file with exactly the same environment and the same outcome then
works, so it must be some slow deterioration or race condition.

Process:         Emacs-10.7 [1191]
Path:            /Applications/Emacs.app/Contents/MacOS/Emacs-10.7
Identifier:      org.gnu.Emacs
Version:         Version 24.3.50 (9.0)
Code Type:       X86-64 (Native)
Parent Process:  launchd [263]
User ID:         501

Date/Time:       2012-12-19 09:44:09.463 +0100
OS Version:      Mac OS X 10.8.2 (12C60)
Report Version:  10

Crashed Thread:  0  Dispatch queue: com.apple.main-thread

Exception Type:  EXC_BAD_ACCESS (SIGABRT)
Exception Codes: EXC_I386_GPFLT

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib              0x00007fff84af3d46 __kill + 10
1   Emacs-10.7                          0x000000010009cd19 
terminate_due_to_signal + 153
2   Emacs-10.7                          0x00000001000b9593 emacs_abort + 19
3   Emacs-10.7                          0x00000001001880bd ns_term_shutdown + 
125
4   Emacs-10.7                          0x000000010009d381 shut_down_emacs + 305
5   Emacs-10.7                          0x000000010009ccdb 
terminate_due_to_signal + 91
6   Emacs-10.7                          0x00000001000b9b06 
deliver_fatal_thread_signal + 134
7   libsystem_c.dylib                   0x00007fff86d468ea _sigtramp + 26
8   libsystem_c.dylib                   0x00007fff86d46650 strlen + 16
9   com.apple.Foundation                0x00007fff8627a99c +[NSString 
stringWithUTF8String:] + 82
10  Emacs-10.7                          0x000000010018deeb ns_run_ascript + 75
11  Emacs-10.7                          0x000000010017dbbf -[EmacsApp 
sendEvent:] + 95
12  com.apple.AppKit                    0x00007fff8573b2fa -[NSApplication run] 
+ 636
13  Emacs-10.7                          0x000000010018a350 ns_read_socket + 560
14  Emacs-10.7                          0x00000001000a88bf gobble_input + 271
15  Emacs-10.7                          0x00000001000a8165 
process_pending_signals + 21
16  Emacs-10.7                          0x0000000100122070 internal_equal + 320
17  Emacs-10.7                          0x000000010011e66d Fequal + 13
18  Emacs-10.7                          0x000000010003bbef display_mode_element 
+ 655
19  Emacs-10.7                          0x000000010003d55d display_mode_element 
+ 7165
20  Emacs-10.7                          0x000000010003d4e2 display_mode_element 
+ 7042
21  Emacs-10.7                          0x000000010003d55d display_mode_element 
+ 7165
22  Emacs-10.7                          0x000000010003d55d display_mode_element 
+ 7165
23  Emacs-10.7                          0x000000010003d8dc display_mode_line + 
364
24  Emacs-10.7                          0x000000010003db30 display_mode_lines + 
336
25  Emacs-10.7                          0x000000010004b36f redisplay_window + 
20879
26  Emacs-10.7                          0x0000000100035676 redisplay_window_0 + 
38
27  Emacs-10.7                          0x0000000100116c83 
internal_condition_case_1 + 307
28  Emacs-10.7                          0x000000010003562c redisplay_windows + 
140
29  Emacs-10.7                          0x0000000100041d9c redisplay_internal + 
4140
30  Emacs-10.7                          0x00000001000aff82 command_loop_1 + 338
31  Emacs-10.7                          0x0000000100116dd9 
internal_condition_case + 297
32  Emacs-10.7                          0x00000001000afe0e command_loop_2 + 62
33  Emacs-10.7                          0x0000000100116ed5 internal_catch + 213
34  Emacs-10.7                          0x00000001000b1840 recursive_edit_1 + 
240
35  Emacs-10.7                          0x00000001000a231d Frecursive_edit + 237
36  Emacs-10.7                          0x000000010009f1c7 main + 5943
37  Emacs-10.7                          0x0000000100001a14 start + 52
[...]

Thread 0 crashed with X86 Thread State (64-bit):
  rax: 0x0000000000000000  rbx: 0x0000000000000028  rcx: 0x00007fff5fbf6ee8  
rdx: 0x0000000000000000
  rdi: 0x00000000000004a7  rsi: 0x0000000000000006  rbp: 0x00007fff5fbf6f10  
rsp: 0x00007fff5fbf6ee8
   r8: 0xfffffffeff8e642f   r9: 0x00000000000001ff  r10: 0x00007fff84af423a  
r11: 0x0000000000000206
  r12: 0x00000001049e6980  r13: 0x0000000000000001  r14: 0x0000000000000006  
r15: 0x00000000000004a7
  rip: 0x00007fff84af3d46  rfl: 0x0000000000000206  cr2: 0x0000000100c015d8
Logical CPU: 0



In GNU Emacs 24.3.50.1 (x86_64-apple-darwin, NS apple-appkit-1038.36)
 of 2012-12-17 on bob.porkrind.org
Bzr revision: 111254 rudalics@gmx.at-20121217075457-afkz5nrni0hvzfkj
Windowing system distributor `Apple', version 10.3.1187
Configured using:
 `configure '--host=x86_64-apple-darwin' '--build=i686-apple-darwin'
 '--with-ns' 'build_alias=i686-apple-darwin'
 'host_alias=x86_64-apple-darwin' 'CC=gcc -mmacosx-version-min=10.7
 -isystem
 
/Users/david/Xcode-10.7_4.5.2/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk/usr/include/
 
-F/Users/david/Xcode-10.7_4.5.2/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk/System/Library/Frameworks''

Important settings:
  value of $LC_CTYPE: UTF-8
  locale-coding-system: nil
  default enable-multibyte-characters: t